An electronic device can include a semiconductor substrate having a front side and a back side; an emitter region closer to the front side than to the back side; a trench extending from a back side surface into the semiconductor substrate, wherein the trench has a sidewall and a bottom; a collector region along the back side surface and spaced apart from the bottom of the trench; a field-stop region lying along the bottom and at least a portion of the sidewall of the trench, wherein the emitter and field-stop regions have one conductivity type, and the collector region has the opposite conductivity type; and a collector terminal along the back side and including a metal-containing material, wherein the collector terminal contacts the collector region and is isolated from the field-stop region. A process of forming the electronic device does not require complex or marginal processing operations.
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1. An electronic device comprising: a semiconductor substrate having a first major side, a second major side opposite the first major side, and a major surface along the second major side; an emitter region closer to the first major side than to the second major side, wherein the emitter region has a first conductivity type; a trench extending from the major surface into the semiconductor substrate, wherein the trench has a sidewall and a bottom; a collector region along the major surface and spaced apart from the bottom of the trench, wherein the collector region has a second conductivity type opposite the first conductivity type; a field-stop region lying along the bottom and at least a portion of a sidewall of the trench, wherein the field-stop region has the first conductivity type; and a collector terminal along the second major side and including a metal-containing material, wherein the collector terminal contacts the collector region and is isolated from the field-stop region.
This invention relates to semiconductor devices, specifically a vertical bipolar junction transistor (BJT) structure designed to improve performance and reliability. The device addresses challenges in conventional BJTs, such as high breakdown voltage and leakage current, by incorporating a field-stop region to control electric field distribution. The device includes a semiconductor substrate with a first major side and a second major side, where the second major side has a major surface. An emitter region of a first conductivity type (e.g., n-type) is positioned closer to the first major side than the second major side. A trench extends from the major surface into the substrate, featuring a sidewall and a bottom. A collector region of a second conductivity type (e.g., p-type) is located along the major surface but spaced apart from the trench bottom. A field-stop region of the first conductivity type is positioned along the trench bottom and at least part of its sidewall, acting as a barrier to prevent excessive electric field penetration. A collector terminal, made of a metal-containing material, is placed along the second major side, electrically contacting the collector region while remaining isolated from the field-stop region to ensure proper device operation. This structure enhances breakdown voltage and reduces leakage by optimizing electric field distribution, making it suitable for high-power applications.
2. The electronic device of claim 1 , further comprising an insulating layer lying along the sidewall and bottom of the trench, wherein the insulating layer is disposed between the field-stop region and the collector terminal.
This invention relates to electronic devices, specifically power semiconductor devices such as insulated gate bipolar transistors (IGBTs) or diodes, which are used in high-voltage applications. A common challenge in such devices is controlling electric field distribution to prevent breakdown and improve reliability. The invention addresses this by incorporating an insulating layer within a trench structure to enhance field management. The device includes a semiconductor substrate with a trench extending into the substrate, where the trench is lined with an insulating layer covering both the sidewall and bottom surfaces. This insulating layer is positioned between a field-stop region (a doped region that helps control electric field distribution) and a collector terminal (the electrode that collects charge carriers). The insulating layer acts as a dielectric barrier, reducing electric field concentration at the trench edges and improving breakdown voltage. By isolating the field-stop region from the collector terminal, the insulating layer prevents direct current leakage paths and enhances device robustness under high-voltage conditions. This configuration is particularly useful in trench-based power devices where precise electric field control is critical for performance and reliability. The insulating layer can be made of materials like silicon dioxide or silicon nitride, depending on the application requirements.
3. The electronic device of claim 2 , wherein the insulating layer substantially fills the trench.
Technical Summary: This invention relates to electronic devices, specifically semiconductor structures with improved insulation in trench regions. The problem addressed is ensuring reliable electrical insulation in semiconductor devices where trenches are formed, particularly to prevent leakage or short circuits between conductive regions. The device includes a semiconductor substrate with a trench formed in its surface. An insulating layer is deposited within the trench, substantially filling it to provide electrical isolation. The insulating layer is composed of a material with high dielectric strength, such as silicon dioxide or a similar dielectric, to prevent current leakage. The trench may be formed through various semiconductor processing techniques, such as etching or ion implantation, and its depth and width are optimized for the specific application. The insulating layer's substantial filling of the trench ensures uniform insulation properties and minimizes voids or gaps that could compromise performance. This is particularly important in high-density semiconductor devices where trenches are closely spaced. The insulating layer may also be planarized after deposition to ensure a smooth surface for subsequent processing steps. The invention may be applied in various semiconductor devices, including transistors, memory cells, or integrated circuits, where trench isolation is required to separate active regions. The substantial filling of the trench by the insulating layer enhances device reliability and manufacturing yield by reducing defects related to incomplete insulation.
4. The electronic device of claim 1 , wherein the field-stop region extends along the sidewall for at least 0.5 micron of the depth of the trench.
This invention relates to semiconductor devices, specifically to an electronic device with an improved trench structure for enhanced performance and reliability. The device includes a semiconductor substrate with a trench formed therein, where the trench has a sidewall and a bottom. A field-stop region is formed along the sidewall of the trench, extending at least 0.5 microns into the depth of the trench. This field-stop region helps control electric field distribution within the device, reducing leakage current and improving breakdown voltage. The trench may be filled with an insulating material, such as an oxide, to electrically isolate adjacent regions of the semiconductor substrate. The field-stop region is doped to create a charge distribution that mitigates field concentration at the trench corners, enhancing the device's robustness under high-voltage conditions. The invention is particularly useful in power semiconductor devices, such as MOSFETs or IGBTs, where minimizing leakage and maximizing breakdown voltage are critical. The field-stop region's depth ensures sufficient charge distribution to effectively shield the trench sidewall from excessive electric fields, improving overall device performance.
5. The electronic device of claim 1 , wherein the field-stop region comprises a buffer region contacting the collector region and having the first conductivity type, wherein the buffer region is spaced apart from the bottom of the trench.
This invention relates to semiconductor devices, specifically to an electronic device with an improved field-stop region for enhanced performance. The device addresses issues in power semiconductor components, such as bipolar junction transistors (BJTs) or insulated-gate bipolar transistors (IGBTs), where excessive electric field concentrations can lead to breakdown or reduced reliability. The electronic device includes a semiconductor substrate with a trench structure extending into the substrate. A collector region of a second conductivity type is formed in the substrate, adjacent to the trench. A field-stop region is provided to control the electric field distribution during device operation. The field-stop region includes a buffer region of a first conductivity type, which directly contacts the collector region. This buffer region is spaced apart from the bottom of the trench, creating a gap that helps manage electric field distribution and prevents premature breakdown. The buffer region's placement and conductivity type ensure that the electric field is uniformly distributed, reducing peak field concentrations near the trench bottom. This design improves the device's robustness and reliability under high-voltage conditions. The buffer region's spacing from the trench bottom also minimizes carrier injection effects, further enhancing performance. The overall structure is optimized for high-voltage applications while maintaining efficient switching characteristics.
6. The electronic device of claim 1 , wherein the field-stop region comprises a first portion, second portion, and a third portion, wherein: the first portion underlies and contacts the collector region, the third portion lies along the bottom of the trench, and the second portion lies along the sidewall of the trench and between the first and third portions, wherein the second portion has a lower dopant concentration as compared to each of the first and third portions.
This invention relates to semiconductor devices, specifically to an electronic device with an improved field-stop region structure for enhanced performance. The problem addressed is optimizing the field-stop region in trench-based semiconductor devices to improve breakdown voltage and reduce leakage current while maintaining efficient charge carrier collection. The electronic device includes a semiconductor substrate with a trench formed therein, a collector region adjacent to the trench, and a field-stop region surrounding the trench. The field-stop region is divided into three distinct portions: a first portion underlying and directly contacting the collector region, a second portion lining the sidewall of the trench, and a third portion located at the bottom of the trench. The second portion, which lies between the first and third portions, has a lower dopant concentration compared to both the first and third portions. This graded dopant distribution helps to control electric field distribution, reducing peak electric fields and improving device reliability. The first portion ensures efficient charge collection from the collector region, while the third portion at the trench bottom provides additional field modulation to prevent premature breakdown. The second portion's lower dopant concentration minimizes leakage paths along the trench sidewall, enhancing overall device performance. This structure is particularly useful in high-voltage semiconductor devices such as insulated gate bipolar transistors (IGBTs) and power diodes.
7. The electronic device of claim 6 , wherein the first portion, the third portion, or both have a peak dopant concentration in a range from 1×10 15 atoms/cm 3 to 1×10 17 atoms/cm 3 .
This invention relates to semiconductor devices, specifically to the doping of regions within an electronic device to improve performance. The problem addressed is optimizing dopant concentration in specific device regions to enhance electrical properties while avoiding excessive doping that could degrade performance. The electronic device includes a substrate with multiple doped regions. A first portion of the device has a peak dopant concentration between 1×10^15 atoms/cm^3 and 1×10^17 atoms/cm^3. A second portion, adjacent to the first, has a different dopant concentration. A third portion, separate from the first and second, also has a peak dopant concentration within the same range. The doping levels are carefully controlled to balance conductivity and leakage current, ensuring efficient charge carrier movement without excessive resistance or unwanted current paths. The device may include additional doped regions, such as a fourth portion with a peak concentration outside the specified range, to further refine electrical behavior. The doping profiles are engineered to create precise conductivity gradients, improving device speed and power efficiency. This approach is particularly useful in transistors, diodes, or other semiconductor components where controlled doping is critical for performance. The invention ensures optimal dopant levels in key regions to achieve desired electrical characteristics while minimizing defects or performance degradation.
8. The electronic device of claim 6 , wherein a peak dopant concentration of the third portion lies at a depth in a range from 0.2 micron to 4 microns from the major surface.
The invention relates to semiconductor devices, specifically to the doping profile of a semiconductor region within an electronic device. The problem addressed is optimizing the dopant concentration and depth distribution in a semiconductor region to improve device performance, such as in transistors or memory cells. The electronic device includes a semiconductor substrate with a major surface and a semiconductor region formed therein. The semiconductor region has a first portion with a first dopant concentration, a second portion with a second dopant concentration, and a third portion with a third dopant concentration. The third portion is positioned between the first and second portions and has a peak dopant concentration located at a specific depth range from the major surface. This peak concentration depth is controlled to be between 0.2 microns and 4 microns, ensuring optimal electrical properties and device functionality. The first portion may have a lower dopant concentration than the third portion, while the second portion may have a higher or lower concentration depending on the device requirements. The doping profile is engineered to enhance carrier mobility, reduce leakage current, or improve other electrical characteristics. The invention is applicable to various semiconductor devices, including but not limited to MOSFETs, memory cells, or other integrated circuit components.
9. The electronic device of claim 1 , wherein the trench has a depth in a range from 10 microns to 25 microns.
The invention relates to electronic devices with improved trench structures, particularly for semiconductor applications. The problem addressed is optimizing trench depth to enhance device performance, such as in power electronics or sensors, where trench dimensions critically impact electrical properties like breakdown voltage, leakage current, and thermal management. The electronic device includes a substrate with a trench formed therein. The trench has a depth specifically controlled within a range of 10 microns to 25 microns. This depth range is selected to balance electrical isolation, mechanical stability, and manufacturing feasibility. Deeper trenches may improve isolation but increase fabrication complexity, while shallower trenches may compromise performance. The trench may be used for various purposes, such as isolating active regions, forming capacitors, or enabling vertical device structures. The trench sidewalls may be vertical or tapered, and the trench may be filled with insulating material, conductive material, or left as an air gap depending on the application. The depth range ensures optimal trade-offs between electrical characteristics and manufacturing efficiency.
10. The electronic device of claim 9 , wherein the trench has a width in a range from 1 micron to 4 microns.
The invention relates to semiconductor devices, specifically to an electronic device with an improved trench structure for enhanced performance. The problem addressed is optimizing the dimensions of trenches in semiconductor devices to improve electrical characteristics while maintaining manufacturability. The electronic device includes a substrate with a trench formed therein, where the trench has a width in the range of 1 micron to 4 microns. The trench is lined with an insulating material, such as an oxide or nitride, and filled with a conductive material, such as polysilicon or metal. The trench structure is used to form components like capacitors, transistors, or isolation regions in integrated circuits. The specified width range ensures proper electrical isolation, reduces leakage current, and improves device reliability while allowing for precise fabrication using standard semiconductor processes. The trench may also include additional features, such as a doped region adjacent to the trench to enhance electrical properties. The device is particularly useful in high-density semiconductor applications where precise control of trench dimensions is critical for performance and yield.
11. The electronic device of claim 1 , wherein the electronic device comprises an insulated gate bipolar transistor that includes the emitter region, the trench, the collector region, the field-stop region, and the collector terminal.
This invention relates to an electronic device incorporating an insulated gate bipolar transistor (IGBT) designed to improve performance and reliability. The IGBT includes an emitter region, a trench, a collector region, a field-stop region, and a collector terminal. The emitter region serves as the source of charge carriers, while the trench structure enhances the electric field distribution, reducing leakage current and improving switching efficiency. The collector region collects charge carriers, and the field-stop region acts as a buffer to prevent excessive electric field penetration, thereby enhancing breakdown voltage and reliability. The collector terminal provides the external connection for the collector region. The IGBT is optimized for high-power applications, offering fast switching speeds, low conduction losses, and robust electrical insulation. The design ensures efficient carrier injection and extraction, minimizing power dissipation and thermal stress. This configuration is particularly useful in power electronics, motor drives, and renewable energy systems where high efficiency and reliability are critical. The IGBT's structure balances electrical performance with thermal management, making it suitable for demanding industrial and automotive applications.
12. A process of forming an electronic device comprising: forming an emitter region having a first conductivity type along a first major side of a semiconductor substrate; thinning the semiconductor substrate to define a major surface along a second major side opposite the first major side, wherein the emitter region is closer to the first major side than the second major side; forming a collector region along the major surface, wherein the collector region has a second conductivity type opposite the first conductivity type; patterning the semiconductor substrate to define a trench extending from the major surface into the semiconductor substrate, wherein the trench has a sidewall and a bottom, and the collector region is spaced apart from the bottom of the trench; forming a field-stop region lying along the bottom and at least a portion of the sidewall of the trench, wherein the field-stop region has the first conductivity type; and forming a collector terminal along the second major side and including a metal-containing material, wherein the collector terminal contacts the collector region and is isolated from the field-stop region.
This invention relates to semiconductor device fabrication, specifically a process for forming a bipolar junction transistor (BJT) with improved electrical characteristics. The process addresses the challenge of minimizing breakdown voltage degradation in high-voltage BJTs while maintaining efficient current flow. The method begins by forming an emitter region of a first conductivity type (e.g., n-type) along one major side of a semiconductor substrate. The substrate is then thinned from the opposite side to create a major surface, ensuring the emitter remains closer to the original substrate side. A collector region of a second conductivity type (e.g., p-type) is formed along this new major surface. A trench is patterned into the substrate from the collector side, extending toward but not reaching the emitter region. A field-stop region of the first conductivity type is formed along the trench's bottom and sidewalls, creating a barrier to prevent excessive electric field penetration. Finally, a metal-containing collector terminal is formed on the collector side, electrically connecting to the collector region while remaining isolated from the field-stop region to avoid short circuits. This structure enhances breakdown voltage by confining the electric field within the trench while maintaining low collector resistance through direct metal-semiconductor contact. The field-stop region prevents punch-through between the emitter and collector, improving device reliability.
13. The process of claim 12 , wherein forming the field-stop region comprises forming a portion of the field-stop region along the second major side, wherein in a finished device, the portion of the field-stop region is spaced apart from the bottom of the trench.
This invention relates to semiconductor device fabrication, specifically to methods for forming field-stop regions in trench-based semiconductor structures. The problem addressed is controlling electric field distribution in semiconductor devices, particularly to prevent breakdown or leakage currents in trench-based structures like insulated gate bipolar transistors (IGBTs) or diodes. The process involves forming a field-stop region adjacent to a trench in a semiconductor substrate. The field-stop region is doped to modify the electric field distribution in the device. A key aspect is forming a portion of the field-stop region along a second major side of the trench, opposite the first major side where the trench is formed. In the finished device, this portion of the field-stop region is spaced apart from the bottom of the trench, ensuring proper electric field management without direct contact between the field-stop region and the trench bottom. This spacing helps prevent excessive field crowding and improves device reliability. The field-stop region is typically formed by ion implantation or diffusion of dopants into the semiconductor substrate. The doping concentration and depth are controlled to achieve the desired electric field distribution. The trench may be filled with an insulating material or a conductive material, depending on the device application. The spacing between the field-stop region and the trench bottom is precisely controlled to optimize device performance while maintaining manufacturability. This technique is particularly useful in high-voltage semiconductor devices where electric field management is critical.
14. The process of claim 13 , wherein forming the collector region and forming the portion of the field-stop region are performed before pattern the semiconductor substrate to define the trench.
The invention relates to semiconductor device fabrication, specifically to methods for forming trench-based semiconductor structures with improved electrical characteristics. The process addresses challenges in controlling electric field distribution and leakage current in semiconductor devices, particularly in trench-based structures like power transistors or diodes. The method involves forming a collector region and a portion of a field-stop region in a semiconductor substrate before patterning the substrate to define a trench. The collector region is a doped region that serves as a terminal for charge carriers, while the field-stop region is a doped region designed to control the electric field distribution near the trench to prevent breakdown and reduce leakage. By forming these regions before trench etching, the process ensures precise alignment and doping profiles, improving device performance and reliability. The trench is subsequently etched into the substrate, and additional steps may include forming insulating layers, gate structures, or other functional regions within the trench. The sequence of forming the collector and field-stop regions before trench patterning allows for better control over doping concentrations and depths, leading to optimized electric field management and reduced parasitic effects. This approach is particularly useful in high-voltage or high-power semiconductor devices where electric field distribution is critical.
15. The process of claim 12 , wherein forming the field-stop region comprises forming a first portion and forming a second portion of the field-stop region, wherein the first portion lies along the bottom of the trench, and the second portion lies along a sidewall of the trench.
This invention relates to semiconductor device fabrication, specifically to methods for forming field-stop regions in trenches to improve electrical performance. The field-stop region is a doped region that helps control electric fields within the device, preventing breakdown and enhancing reliability. The challenge addressed is achieving precise field-stop region formation to optimize device performance while maintaining manufacturability. The process involves forming a trench in a semiconductor substrate, followed by the creation of a field-stop region within the trench. The field-stop region is divided into two distinct portions: a first portion located along the bottom of the trench and a second portion along the sidewall of the trench. The first portion provides electrical isolation at the trench base, while the second portion along the sidewall helps manage lateral electric fields. This dual-portion structure ensures uniform field distribution, reducing leakage current and improving breakdown voltage. The field-stop region is typically formed through selective doping techniques, such as ion implantation or diffusion, tailored to the specific semiconductor material and device requirements. The first and second portions may be doped differently to optimize their respective functions. This approach enhances device reliability and performance in applications like power electronics, where precise electric field control is critical. The method ensures consistent field-stop region formation, addressing variability issues in conventional processes.
16. The process of claim 15 , wherein forming the second portion of the field-stop region comprises implanting a dopant at different tilt angles during different ion implantations.
The invention relates to semiconductor manufacturing, specifically to methods for forming field-stop regions in semiconductor devices to improve electrical performance and reliability. The field-stop region is a doped region that prevents electric field penetration into underlying layers, reducing leakage current and enhancing device robustness. A challenge in forming such regions is achieving uniform doping profiles while minimizing damage to the semiconductor substrate. The process involves forming a field-stop region in a semiconductor substrate by implanting a dopant at different tilt angles during multiple ion implantation steps. The field-stop region is divided into at least two portions, where the second portion is formed by implanting ions at varying tilt angles in different implantation steps. This technique allows precise control over the doping profile, ensuring uniform concentration and reducing defects caused by ion implantation. The first portion of the field-stop region may be formed using a standard vertical implantation, while the second portion is implanted at non-zero tilt angles to achieve deeper or more uniform doping. The method improves device performance by optimizing the electric field distribution and minimizing leakage current.
17. The process of claim 12 , further comprising laser annealing to activate dopants for the collector region and the field-stop regions.
This invention relates to semiconductor device fabrication, specifically to a process for forming a collector region and field-stop regions in a semiconductor substrate. The process addresses the challenge of efficiently activating dopants in these regions to improve device performance. The method involves implanting dopants into the substrate to form the collector and field-stop regions, followed by laser annealing to activate the implanted dopants. Laser annealing provides precise control over thermal energy delivery, enabling rapid activation without excessive thermal diffusion, which can degrade device characteristics. The field-stop regions are formed adjacent to the collector region to manage electric field distribution, preventing breakdown and enhancing reliability. The laser annealing step ensures uniform dopant activation while minimizing thermal damage to surrounding structures. This approach improves device efficiency and reliability by optimizing dopant activation in critical regions. The process is particularly useful in high-voltage semiconductor devices where precise control of dopant profiles is essential.
18. The process of claim 12 , further comprising forming an insulating layer along the bottom and sidewall of the trench, wherein the insulating layer is disposed between the field-stop region and the collector terminal.
The invention relates to semiconductor device fabrication, specifically to methods for forming insulated trenches in power semiconductor devices to improve electrical performance. The problem addressed is the need to prevent electrical interference between a field-stop region and a collector terminal in trench-based semiconductor structures, which can degrade device efficiency and reliability. The process involves etching a trench into a semiconductor substrate, where the trench is adjacent to a field-stop region. An insulating layer is then formed along the bottom and sidewalls of the trench, ensuring it is positioned between the field-stop region and the collector terminal. This insulating layer electrically isolates the field-stop region from the collector terminal, reducing leakage current and improving device performance. The insulating layer may be formed using techniques such as thermal oxidation, chemical vapor deposition, or atomic layer deposition, depending on the material and thickness requirements. The field-stop region is typically a doped region that controls the electric field distribution within the device, while the collector terminal is a conductive region that collects charge carriers. By insulating the trench, the process enhances the breakdown voltage and reduces parasitic capacitance, making the device more efficient for high-power applications.
19. The process of claim 18 , wherein forming the insulating layer comprises depositing an insulating material using a plasma-enhanced deposition with tetraethyl orthosilicate as a precursor of an insulating material within the insulating layer.
This invention relates to semiconductor manufacturing, specifically to processes for forming insulating layers in integrated circuits. The problem addressed is achieving high-quality insulating layers with precise composition and uniformity, which is critical for device performance and reliability. The invention describes a method for forming an insulating layer by depositing an insulating material using plasma-enhanced deposition with tetraethyl orthosilicate (TEOS) as a precursor. This technique enhances deposition efficiency and film uniformity while ensuring the insulating layer has the desired electrical and mechanical properties. The process involves introducing TEOS into a deposition chamber, where it reacts under plasma conditions to form a silicon dioxide (SiO2) layer. The plasma enhances the reaction rate and improves film density and conformality, which are essential for modern semiconductor devices. The method may also include additional steps such as surface preparation, temperature control, and post-deposition treatments to optimize layer properties. This approach is particularly useful in applications requiring high-quality dielectric layers, such as in transistors, capacitors, or interconnect structures. The use of TEOS as a precursor ensures a reliable and scalable deposition process, making it suitable for advanced semiconductor fabrication.
20. The process of claim 18 , wherein forming the insulating layer comprises filling the trench with an insulating material.
The invention relates to semiconductor manufacturing, specifically to processes for forming insulating layers in integrated circuits. The problem addressed is the need for precise and reliable insulation between conductive features, such as transistors or interconnects, to prevent electrical interference and ensure proper device functionality. The process involves creating a trench in a substrate, which is then filled with an insulating material to form an insulating layer. The trench may be formed using etching techniques, such as dry or wet etching, to define the desired shape and depth. The insulating material, which may include oxides, nitrides, or other dielectric materials, is deposited into the trench using methods like chemical vapor deposition (CVD) or physical vapor deposition (PVD). The material is then planarized, typically through chemical-mechanical polishing (CMP), to ensure a flat surface for subsequent processing steps. This method ensures that the insulating layer is uniformly deposited and conformally fills the trench, providing effective electrical isolation. The process is particularly useful in advanced semiconductor devices where high-density integration requires precise insulation between closely spaced features. By filling the trench with an insulating material, the method minimizes voids or defects that could compromise device performance. The technique is compatible with various semiconductor fabrication processes and can be applied to different types of insulating materials depending on the specific requirements of the device.
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September 11, 2018
January 28, 2020
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